Physical Adsorption‐Driven Assembly of Au‐Locked Nucleic Acid (LNA) Probes on MoS ₂ Nanosheets for SERS‐Based Detection of microRNAs (miRNAs)

Abstract Developing sensitive and cost‐effective biosensors is critical for detecting clinically relevant biomarkers such as microRNAs (miRNAs). Herein, a novel surface‐enhanced Raman scattering (SERS) platform is fabricated based on the physical adsorption‐driven assembly of gold–locked nucleic acid (Au‐LNA) nanohybrids onto molybdenum disulfide (MoS 2 ) nanosheets for the indirect detection of miR‐210‐3p. Leveraging the inherent physicochemical properties of AuNPs and MoS 2 , synergy, and non‐covalent interactions, Au‐LNA nanohybrids are immobilized onto MoS 2 , forming a stable plasmonic nanocomposite. Characterization of the nanohybrids and nanocomposites showcased successful hybridization, conjugation, surface assembly, and performance capabilities via a physical adsorption mechanism of synthesis . Cy3 Raman reporter facilitates sensitive monitoring of hybridization and timmobilization. The nanocomposite exhibits a strong and concentration‐dependent SERS response at ≈1389, and 1585 cm −1 Cy3 signature peaks. Comparatively, ≈1585 cm −1 , showed superior signal amplification, stability, and reliability, and a strong linear correlation range (R 2 = 0.92) with a detection limit of 11 n m . Matched to existing MoS 2 ‐based biosensing strategies, this platform exhibits comparable sensitivity, signal amplification, and simplicity in fabrication. This work demonstrates the practicality of physical adsorption as an effective strategy for SERS biosensor assembly and highlights the platform's potential for scalable label‐integrated detection of miRNAs and low‐abundant biomarkers.